This application claims the priority of Korean Patent Application No. 2002-39152 filed Jul. 6, 2002 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to an optical disk drive, and more particularly, to a tray locking apparatus which is made slim to be adopted in a slim optical disk drive.
2. Description of the Related Art
In general, optical disk drives record information on a disk medium, such as a compact disk (CD) or digital video disk (DVD), and reproduce information therefrom. A tray on which the disk is mounted is installed in the optical drive to slide in and out of a body. Typical optical disk drives are loaded and unloaded by a loading motor. A tray installed in a slim optical disk drive used for a notebook computer, however, manually slides in and out of the slim optical disk drive, and thus, a tray locking apparatus to lock or unlock the tray with respect to a body is needed.
FIG. 1 shows an optical disk drive adopting a conventional tray locking apparatus. Referring to the drawing, the optical disk drive includes a fixed frame 110, a tray 120 sliding in and out with respect to the fixed frame 110, a spindle motor 130 rotating a disk, an optical pickup portion 140 to record or reproduce information on and from the disk, and a locking apparatus 150 locking and unlocking the tray 120.
FIGS. 2 and 3 show states in which the tray is locked and unlocked, respectively, by the tray locking apparatus shown in FIG. 1. Referring to FIG. 2, a solenoid 160 having a mobile piece 161, a first arm 170 connected to the mobile piece 161 and pivoting according to movement of the mobile piece 161, and a locking arm 180 connected to the first arm 170 are provided on the tray 130. A locking post 115 is installed on the fixed frame 110.
A first gear portion 171 is located on a pivot shaft of the first arm 170. A hook portion 181 that engages the locking post 115, and a second gear portion 182 engaged with the first gear portion 171 to pivot the locking arm 180, are provided on the locking arm 180. A spring 190, providing an elastic force to bias the locking arm 180 in a direction in which the locking post 115 and the hook portion 181 are coupled, is installed at one end of the locking arm 180.
FIG. 3 shows the operation of the conventional tray locking apparatus shown in FIG. 2. When current is applied to the solenoid 160, the mobile piece 161 is moved by a magnetic force of the solenoid 160 to the left on the drawing, so that the first arm 170 connected to the mobile piece 161 pivots clockwise on the drawing. Then the locking arm 180, having the second gear portion 182 engaged to the first gear portion 171, pivots counterclockwise so that the hook portion 181 is released from the locking post 115. In this state, the tray 120 is manually pulled to to unload the disk.
When the application of current to the solenoid 160 is stopped, the mobile piece 161 returns to the original position and the locking arm 180 is returned to the original position by the spring 190. In this state, when the tray 120 is manually pushed to load the disc, the hook portion 181 and the locking post 115 are engaged so that the tray 120 is locked.
To prevent unlocking of the tray 120 by an impact, the elastic force of the spring 190, by which the hook portion 181 and the locking post 115 are coupled, needs to be as great as possible. To unlock the tray 120, however, the operational force imparted to the mobile piece 161 by the solenoid 160 must be greater than the elastic force of the spring 190. Thus, to increase the elastic force of the spring 190, the operational force imparted to the mobile piece 161 needs to increase commensurately.
But to increase the operational force of the mobile piece 161, a large solenoid is used, or the amount of current applied to the solenoid needs to be increased. Since, in general, there is a limit to the amount of available current in a notebook computer, a large solenoid having a great capacity is used. But the use of a large solenoid hinders making a slim optical disk drive, and increases the cost.